Sailboarding since its introduction in the 1970s has become an international sport of major proportions and is considered to be the fastest growing water sport in the world. Sailboards are used in conditions ranging from a slight breeze on a calm lake to gale force winds in rough ocean surf.
A sailboard usually consists of a substantially flat, elongated board, a sail system, an optional centerboard system, and a fixed fin mounted aft. Much of the design of the sailboard has been borrowed directly from surfboards, including the fixed fin. A component originally designed for surfing that is used almost universally on sailboards is the adjustable fin holder. The adjustable fin holder allows longitudinal adjustment of the fixed fin's position while the board is out of water, as well as easy installation and removal of the fin.
Because of the versatility and shallow drafts of sailboards, these craft are often sailed in areas where the aft mounted fin will come into contact with an underwater obstruction, such as rock, reef, underwater debris, or the bottom of the sailing area. Damage due to the fin striking an underwater object may result in the following:
1. Breaking of the fin PA1 2. Breaking of the fin holder box PA1 3. Delamination of the fin holder from the board structure PA1 4. Any combination of the above PA1 U.S. Pat. No. 3,846,030 PA1 U.S. Pat. No. 4,052,826 PA1 U.S. Pat. No. 4,528,924 PA1 U.S. Pat. No. 4,701,144 PA1 DE No. 31 29 566 PA1 FR No. 2,510,968
Replacement or repair of the damage described above is in most cases very costly. It is therefore highly desirable to fasten the fin to the fin holder in such a manner as to protect the fin and more expensive fin fastening components from damaging overloads.